A2 Biology: Breathing & using a spirometer

BREATHINGTIDAL VOLUME: the volume of air we breathe in and out at each breadth.VITAL CAPACITY: the maximum volume of air we can inhale and exhale.MINUTE VENTILATION: the volume of air taken into the lungs in one minute.Minute ventilation = tidal volume (average volume of one breath) X breathing rate (number of breaths per minute) The fall in the trace is due to the consumption of oxygen by the subject. The rate of oxygen consumption can be calculated by dividing the decrease in volume by time for the fall. A person using a spirometer breathes in and out of an airtight chamber causing it to move up and down and leaving a trace on a kymograph. This can be used to investigates effects of exercise by connecting it to someone doing exercise e.g. on a treadmill.